1. Field of the Invention
The invention relates to a physical exerciser. More particularly, it relates to an exerciser of the type wherein manual pressure is exerted, to compress a set of springs, so as to exercise certain groups of muscles of the human body.
2. Prior Art
Physical exercisers of the compression spring type are readily available commercially. Such devices usually involve providing a spring extending longitudinally within a pair of telescoping cylinders. This spring may be compressed by sliding the cylinders together. This compressing action involves the muscles performing work.
These exercisers are sometimes combined with an endless rope assembly, so as to provide a dual purpose push-pull physical exercising device.
Exemplary of this type of prior art device is that disclosed in U.S. Pat. No. 4,290,600 issued to G. F. Kolbel. Therein is described an exerciser comprising a central tube. A pair of end tubes, each having a handle at its outer end, a slidably and telescopically mounted on the ends of the central tube. A single spring, which extends the full length of the assembly, is positioned to extend through and beyond the ends of the central tube. The end tubes contain the spring ends and can be moved inwardly along the central tube, against the resistance of the spring.
U.S. Pat. Nos. 3,741,539, 3,343,837, 3,759,514 and 3,268,225, further exemplify compression spring-type exercisers.
However, these prior art devices suffer two common disadvantages, namely: (a) the excessive length of the unit; and (b) the limited range of motion permitted, which prevents the outstretched arms from being brought close together. These drawbacks arise from the limitations of the mechanical properties of the spring. Prevention of spring failure by fatigue and preservation of spring resilience dictate that the maximum permissible compression of the spring should be restricted to about one-third the length thereof. Thus, to provide a full range of motion for exercising, most particularly the muscles of the upper torso, spring size requirements have, heretofore, resulted in a device having a length which extends beyond the width of the human body. The arms, therefore, are overextended at the commencement of the compression movement. Further, the range of sliding handle movement along the length of the tube is limited to one-third the length of the spring, thereby preventing bringing the arms closely together at a central anterior position.
Ideally, muscular exercise requires that the muscle be permitted to contract over a substantial range of its potential movement. In addition, the load exerted on the muscle during its contraction should be sustained, or increased incrementally, throughout its range of movement. The prior art, compression spring devices fall short in meeting these requirements.
There is, therefore a need for such a device characterized by the following features:
a length more proportional to the width of the human body; PA1 sliding handles which may be brought more closely together adjacent the longitudinal mid-point of the device; and PA1 an arrangement wherein the spring resistance action is substantially consistent throughout the compressive movement.